A controlled source electromagnetic (CSEM) survey technique can be used to perform a survey of a subterranean structure for identifying elements of interest, such as hydrocarbon-bearing reservoirs, gas injection zones, thin carbonate or salt layers, fresh-water aquifers, and so forth. With CSEM surveying, an electromagnetic (EM) transmitter is used to generate EM signals. EM receivers can be deployed in an area of interest to make measurements from which information about the subterranean structure can be derived. The EM receivers may include a number of sensors for detecting any combination of electric fields, electric currents, and magnetic fields.
In some marine CSEM survey arrangements, the EM receivers can be provided on the water bottom surface, such as the sea floor. In other marine survey arrangements, the EM receivers can be towed by a marine vessel. When sea floor EM receivers are used, a substantial amount of time can be spent deploying the EM receivers. On the other hand, in a fully towed system, the cables that carry the EM receivers are relatively long, since typical CSEM survey arrangements involve making measurements at multiple source-receiver offsets.